June, the Yan forces successfully destroyed the main food storage of the government forces in Pei, and Dezhou was on the brink of collapse. In July, the Yan forces captured Pengde and Linxian. On 10 July, government forces from Zhending launched a raid on Beiping. Zhu Di divided the army to reinforce Beiping and defeated the government forces by 18 September. In hope to reverse the tides of the battle, imperial advisor Fang Xiaoru attempted to intensify the existing distrust between the first and second son of Zhu Di, Zhu Gaochi and Zhu Gaoxu, but the strategy failed once again. On 15 July, government forces led by Fang Zhao from Datong began to approach Baoding, threatening Beiping, and Zhu Di was forced to withdraw. The Yan forces had a decisive victory in Baoding on 2 October, and Fang Zhao retreated back to Datong. On 24 October, the Yan forces returned to Beiping. The government forces from Liaodong attempted to raid the city again, but the attack was repelled. The Jingnan Campaign had been ongoing for more than two years up until this point. Despite numerous victories, the Yan forces were unable to hold on to territories due to lack of manpower. Yan offensives, 1401–1402 Advancing south By the winter of 1401, Zhu Di decided to alter the general offensive strategy. The Yan forces were to skip the strongholds of the government forces, and advance straight south toward the Yangtze River. On 2 December, the Yan forces mobilised and began advancing southward. In the month of January, the Yan forces stormed across Shandong and captured Dong'e, Dongping, Wenshang, and Pei. On 30 January 1402, the Yan forces reached Xuzhou, the major transportation hub. In response to the mobilisation of the Yan forces, Jianwen Emperor ordered Mei Ying to defend Huai'an, and ordered Xu Huizu to reinforce Shandong. On 21 February, the government forces in Xuzhou refused to engage with the Yan forces to focus on defending the city after suffering a defeat. Battle of Lingbi Zhu Di decided to skip Xuzhou and continued to advance southward. The Yan forces went past Suzhou, defended by Pin An, and reached Bengbu by 9 March. Ping An pursued the Yan forces but was ambushed by Zhu Di at Fei River on 14 March, which forced the Pin An to retreat back to Suzhou. On 23 March, Zhu Di dispatched an army to disrupt the